Search Publications
The PDS 66 Circumstellar Disk as Seen in Polarized Light with the Gemini Planet Imager
Schneider, Glenn; Duchêne, Gaspard; Dong, Ruobing +25 more
We present H- and K-band imaging polarimetry for the PDS 66 circumstellar disk obtained during the commissioning of the Gemini Planet Imager (GPI). Polarization images reveal a clear detection of the disk in to the 0.″12 inner working angle (IWA) in the H band, almost three times closer to the star than the previous Hubble Space Telescope (HST) ob…
The Spectacular Radio-near-IR-X-Ray Jet of 3C 111: The X-Ray Emission Mechanism and Jet Kinematics
Perlman, Eric S.; Clautice, Devon; Cara, Mihai +6 more
Relativistic jets are the most energetic manifestation of the active galactic nucleus (AGN) phenomenon. AGN jets are observed from the radio through gamma-rays and carry copious amounts of matter and energy from the sub-parsec central regions out to the kiloparsec and often megaparsec scale galaxy and cluster environs. While most spatially resolve…
Constraining the ISM Properties of the Cloverleaf Quasar Host Galaxy with Herschel Spectroscopy
Maloney, Philip R.; Uzgil, Bade D.; Bradford, C. Matt +2 more
We present Herschel observations of the far-infrared (FIR) fine-structure (FS) lines [C II]158 µm, [O I]63 µm, [O III]52 µm, and [Si II]35 µm in the z = 2.56 Cloverleaf quasar, and combine them with published data in an analysis of the dense interstellar medium (ISM) in this system. Observed [C II]158 µm, [O I]63 &mic…
Infrared Supernova Remnants and their Infrared-to-X-ray Flux Ratios
Jeong, Il-Gyo; Seok, Ji Yeon; Koo, Bon-Chul +2 more
Recent high-resolution infrared space missions have revealed supernova remnants (SNRs) of diverse morphology in infrared (IR) dust emission that are often very different from their X-ray appearance. The observed range of infrared-to-X-ray (IRX) flux ratios of SNRs is also wide. For a sample of 20 Galactic SNRs, we obtain their IR and X-ray propert…
Compositional Similarities and Distinctions between Titan’s Evaporitic Terrains
Barnes, Jason W.; MacKenzie, S. M.
We document the similarities in composition between the equatorial basins Tui Regio, Hotei Regio, and other 5-µm-bright materials, notably the north polar evaporites, by investigating the presence and extent of an absorption feature at 4.92 µm. In most observations, Woytchugga Lacuna, Ontario Lacus, MacKay Lacus, deposits near Fensal, …
Tracing the Chromospheric and Coronal Magnetic Field with AIA, IRIS, IBIS, and ROSA Data
Aschwanden, Markus J.; Reardon, Kevin; Jess, Dave B.
The aim of this study is to explore the suitability of chromospheric images for magnetic modeling of active regions. We use high-resolution images (≈ 0\buildrel{\prime\prime}\over{.} 2{--}0\buildrel{\prime\prime}\over{.} 3), from the Interferometric Bidimensional Spectrometer in the Ca II 8542 Å line, the Rapid Oscillations in the Solar Atmosphere…
A Study of the Relation between Star Formation and Molecular Clumps on Subparsec Scales in 30 Doradus
Panagia, N.; Indebetouw, R.; Sabbi, E. +4 more
We present 12CO and 13CO molecular gas data observed by ALMA, massive early-stage young stellar objects (YSOs) identified by applying color-magnitude cuts to Spitzer and Herschel photometry, and low-mass late-stage YSOs identified via {{H}}α excess. Using dendrograms, we derive properties for the molecular cloud structures. T…
The Rotation of the Solar Photospheric Magnetic Field
Xu, J. C.; Gao, P. X.
The rotational characteristics of the solar photospheric magnetic field at four flux ranges are investigated together with the total flux of active regions (MFar) and quiet regions (MFqr). The first four ranges (MF1-4) are (1.5-2.9) × 1018, (2.9-32.0) × 1018, (3.20-4.27) × 1019, and…
A Deep X-Ray View of the Bare AGN Ark 120. I. Revealing the Soft X-Ray Line Emission
Turner, T. J.; Porquet, D.; Reeves, J. N. +3 more
The Seyfert 1 galaxy Ark 120 is a prototype example of the so-called class of bare nucleus active galactic nuclei (AGNs), whereby there is no known evidence for the presence of ionized gas along the direct line of sight. Here deep (>400 ks exposure), high-resolution X-ray spectroscopy of Ark 120 is presented from XMM-Newton observations that we…
A Deep X-Ray View of the Bare AGN Ark 120. II. Evidence for Fe K Emission Transients
Porquet, D.; Matt, G.; Reeves, J. N. +3 more
We report on the results from a large observational campaign on the bare Seyfert galaxy Ark 120, jointly carried out in 2014 with XMM-Newton, Chandra, and NuSTAR. The fortunate line of sight to this source, devoid of any significant absorbing material, provides an incomparably clean view to the nuclear regions of an active galaxy. Here we focus on…